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Tuba Bayraktar - One of the best experts on this subject based on the ideXlab platform.
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Size and expansion ratio analysis of micro Nozzle gas flow ☆
2020Co-Authors: Omer San, Ilhan Bayraktar, Tuba BayraktarAbstract:a b s t r a c t a r t i c l e i n f o Available online 17 March 2009 Keywords: Micro Nozzle Burnett equations MEMS (Micro Electro-Mechanical Systems) Size and expansion ratio effects on the flowfield are investigated for micro converging-diverging Nozzles. Numerical computations are conducted by using two dimensional augmented Burnett equations and NavierStokes equations that were derived from the Boltzmann equation. The Maxwell-Smoluchowski slip boundary condition is used for adiabatic walls, and Steger-Warming flux vector splitting scheme is applied to the convective inviscid flux terms. The results from the augmented Burnett equation are compared with NavierStokes and Direct Simulation Monte Carlo (DSMC) results. Then, Nozzle-Size analysis is conducted for between 2 µm and 100 µm throat width. Influence of the Knudsen number is investigated, and temperature and Mach number variations are presented. In addition, the influence of the expansion ratio is studied with three (1.7:1, 3.4:1, and 6.8:1) different configurations. The results are compared with each other and an experimental data in the literature
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Size and expansion ratio analysis of micro Nozzle gas flow
International Communications in Heat and Mass Transfer, 2009Co-Authors: Omer San, Ilhan Bayraktar, Tuba BayraktarAbstract:Abstract Size and expansion ratio effects on the flowfield are investigated for micro converging-diverging Nozzles. Numerical computations are conducted by using two dimensional augmented Burnett equations and Navier-Stokes equations that were derived from the Boltzmann equation. The Maxwell-Smoluchowski slip boundary condition is used for adiabatic walls, and Steger-Warming flux vector splitting scheme is applied to the convective inviscid flux terms. The results from the augmented Burnett equation are compared with Navier-Stokes and Direct Simulation Monte Carlo (DSMC) results. Then, Nozzle-Size analysis is conducted for between 2 µm and 100 µm throat width. Influence of the Knudsen number is investigated, and temperature and Mach number variations are presented. In addition, the influence of the expansion ratio is studied with three (1.7:1, 3.4:1, and 6.8:1) different configurations. The results are compared with each other and an experimental data in the literature.
Drago Subaric - One of the best experts on this subject based on the ideXlab platform.
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hazelnut oil production using pressing and supercritical co2 extraction
Hemijska Industrija, 2016Co-Authors: Stela Jokic, Krunoslav Aladic, Tihomir Moslavac, Mate Bilic, đurđica Ackar, Drago SubaricAbstract:In the hazelnut oil production it is very important to find an appropriate method to recover the oil from kernels. The objective of this study was to evaluate the oil extraction process from hazelnuts by screw pressing followed by extraction with supercritical CO2. The effects of temperature head presses, frequency and Nozzle Size in pressing experiments on oil temperature and recovery were monitored. The optimal pressing condition using response surface methodology was determined. In obtained hazelnut oil the following quality parameters were determined: peroxide value 0 mmol O2/kg, free fatty acids 0.23%, insoluble impurities 0.42%, moisture content 0.045%, iodine value 91.55 g I2/100 g, saponification value 191.46 mg KOH/g and p- anisidine value 0.19. Rosemary extract was the most effective in protecting the oil from oxidative deterioration. The residual oil that remained in the cake after pressing was extracted totally with supercritical CO2 and such defatted cake, free of toxic solvents, can be used further in other processes.
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cold pressing and supercritical co2 extraction of hemp cannabis sativa seed oil
Chemical and Biochemical Engineering Quarterly, 2015Co-Authors: Krunoslav Aladic, Stela Jokic, Tihomir Moslavac, Srecko Tomas, Senka Vidovic, Jelena Vladic, Drago SubaricAbstract:In a past few decades the variety of hemp Cannabis sativa L. was unfairly neglected because of the similarity with the kind of hemp that is illegal and is used as a narcotic. The objective of this study was to evaluate the oil extraction process from Cannabis sativa seeds by cold pressing followed by extraction with supercritical CO2. In pressing experiments, the response surface methodology was conducted in order to study the effects of temperature, frequency and Nozzle Size on oil recovery and quality parameters. The optimal condition to obtain the highest oil recovery and the best oil quality within the experimental range of the variables studied was at temperature of 60 °C, frequency of 20 Hz and using Nozzle of ID 6 mm. The residual oil in the press cake was totally extracted by supercritical CO2 in newly designed and built supercritical fluid extraction system. The oregano essential oil was the most effective in protecting the oil from oxidative deterioration.
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pressing and supercritical co2 extraction of camelina sativa oil
Industrial Crops and Products, 2014Co-Authors: Tihomir Moslavac, Krunoslav Aladic, Stela Jokic, Drago Subaric, Josipa Vukoja, Nikolina PrceAbstract:Abstract The objective of this study was to evaluate the oil extraction process from Camelina sativa (L.) Crantz seeds by screw pressing followed by extraction with supercritical CO2. In pressing experiments, the response surface methodology (RSM) was conducted in order to study the effects of temperature, frequency and Nozzle Size on oil recovery and quality parameters. The optimal condition to obtain the highest oil recovery and the best oil quality within the experimental range of the variables studied was at temperature of 52 °C, frequency of 20 Hz and using Nozzle of ID 9 mm. The experimental values agreed with those predicted, thus indicating suitability of the used models and the success of RSM in optimizing the pressing conditions of investigated system. The cake resulting from pressing at optimal conditions was extracted with CO2 in a new designed and built a homemade supercritical fluid extraction system. The residual oil in the pressed cake was almost totally extracted by supercritical CO2. The aim of this study was also to investigate the influence of natural antioxidant (rosemary extract Oxy.Less CS, Oxy.Less CLEAR and StabilEnhance OSR, green tea extract, olive leaf extract, pomegranate extract) on the oxidative stability of C. sativa oil. The rosemary extract Oxy.Less CS in concentration of 0.3% was the most effective in protecting the oil from oxidative deterioration.
Tihomir Moslavac - One of the best experts on this subject based on the ideXlab platform.
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hazelnut oil production using pressing and supercritical co2 extraction
Hemijska Industrija, 2016Co-Authors: Stela Jokic, Krunoslav Aladic, Tihomir Moslavac, Mate Bilic, đurđica Ackar, Drago SubaricAbstract:In the hazelnut oil production it is very important to find an appropriate method to recover the oil from kernels. The objective of this study was to evaluate the oil extraction process from hazelnuts by screw pressing followed by extraction with supercritical CO2. The effects of temperature head presses, frequency and Nozzle Size in pressing experiments on oil temperature and recovery were monitored. The optimal pressing condition using response surface methodology was determined. In obtained hazelnut oil the following quality parameters were determined: peroxide value 0 mmol O2/kg, free fatty acids 0.23%, insoluble impurities 0.42%, moisture content 0.045%, iodine value 91.55 g I2/100 g, saponification value 191.46 mg KOH/g and p- anisidine value 0.19. Rosemary extract was the most effective in protecting the oil from oxidative deterioration. The residual oil that remained in the cake after pressing was extracted totally with supercritical CO2 and such defatted cake, free of toxic solvents, can be used further in other processes.
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cold pressing and supercritical co2 extraction of hemp cannabis sativa seed oil
Chemical and Biochemical Engineering Quarterly, 2015Co-Authors: Krunoslav Aladic, Stela Jokic, Tihomir Moslavac, Srecko Tomas, Senka Vidovic, Jelena Vladic, Drago SubaricAbstract:In a past few decades the variety of hemp Cannabis sativa L. was unfairly neglected because of the similarity with the kind of hemp that is illegal and is used as a narcotic. The objective of this study was to evaluate the oil extraction process from Cannabis sativa seeds by cold pressing followed by extraction with supercritical CO2. In pressing experiments, the response surface methodology was conducted in order to study the effects of temperature, frequency and Nozzle Size on oil recovery and quality parameters. The optimal condition to obtain the highest oil recovery and the best oil quality within the experimental range of the variables studied was at temperature of 60 °C, frequency of 20 Hz and using Nozzle of ID 6 mm. The residual oil in the press cake was totally extracted by supercritical CO2 in newly designed and built supercritical fluid extraction system. The oregano essential oil was the most effective in protecting the oil from oxidative deterioration.
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pressing and supercritical co2 extraction of camelina sativa oil
Industrial Crops and Products, 2014Co-Authors: Tihomir Moslavac, Krunoslav Aladic, Stela Jokic, Drago Subaric, Josipa Vukoja, Nikolina PrceAbstract:Abstract The objective of this study was to evaluate the oil extraction process from Camelina sativa (L.) Crantz seeds by screw pressing followed by extraction with supercritical CO2. In pressing experiments, the response surface methodology (RSM) was conducted in order to study the effects of temperature, frequency and Nozzle Size on oil recovery and quality parameters. The optimal condition to obtain the highest oil recovery and the best oil quality within the experimental range of the variables studied was at temperature of 52 °C, frequency of 20 Hz and using Nozzle of ID 9 mm. The experimental values agreed with those predicted, thus indicating suitability of the used models and the success of RSM in optimizing the pressing conditions of investigated system. The cake resulting from pressing at optimal conditions was extracted with CO2 in a new designed and built a homemade supercritical fluid extraction system. The residual oil in the pressed cake was almost totally extracted by supercritical CO2. The aim of this study was also to investigate the influence of natural antioxidant (rosemary extract Oxy.Less CS, Oxy.Less CLEAR and StabilEnhance OSR, green tea extract, olive leaf extract, pomegranate extract) on the oxidative stability of C. sativa oil. The rosemary extract Oxy.Less CS in concentration of 0.3% was the most effective in protecting the oil from oxidative deterioration.
John A Rogers - One of the best experts on this subject based on the ideXlab platform.
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scaling laws for jet pulsations associated with high resolution electrohydrodynamic printing
Applied Physics Letters, 2008Co-Authors: Hong Kyoon Choi, Jangung Park, Ok O Park, Placid Mathew Ferreira, John G Georgiadis, John A RogersAbstract:This paper presents simple scaling laws that describe the intrinsic pulsation of a liquid jet that forms at the tips of fine Nozzles under electrohydrodynamically induced flows. The jet diameter is proportional to the square root of the Nozzle Size and inversely proportional to the electric field strength. The fundamental pulsation frequency is proportional to the electric field strength raised to the power of 1.5. These scaling relationships are confirmed by experiments presented here and by data from the literature. The results are important for recently developed high-resolution ink jet printing techniques and other applications using electrohydrodynamics.
Stela Jokic - One of the best experts on this subject based on the ideXlab platform.
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hazelnut oil production using pressing and supercritical co2 extraction
Hemijska Industrija, 2016Co-Authors: Stela Jokic, Krunoslav Aladic, Tihomir Moslavac, Mate Bilic, đurđica Ackar, Drago SubaricAbstract:In the hazelnut oil production it is very important to find an appropriate method to recover the oil from kernels. The objective of this study was to evaluate the oil extraction process from hazelnuts by screw pressing followed by extraction with supercritical CO2. The effects of temperature head presses, frequency and Nozzle Size in pressing experiments on oil temperature and recovery were monitored. The optimal pressing condition using response surface methodology was determined. In obtained hazelnut oil the following quality parameters were determined: peroxide value 0 mmol O2/kg, free fatty acids 0.23%, insoluble impurities 0.42%, moisture content 0.045%, iodine value 91.55 g I2/100 g, saponification value 191.46 mg KOH/g and p- anisidine value 0.19. Rosemary extract was the most effective in protecting the oil from oxidative deterioration. The residual oil that remained in the cake after pressing was extracted totally with supercritical CO2 and such defatted cake, free of toxic solvents, can be used further in other processes.
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cold pressing and supercritical co2 extraction of hemp cannabis sativa seed oil
Chemical and Biochemical Engineering Quarterly, 2015Co-Authors: Krunoslav Aladic, Stela Jokic, Tihomir Moslavac, Srecko Tomas, Senka Vidovic, Jelena Vladic, Drago SubaricAbstract:In a past few decades the variety of hemp Cannabis sativa L. was unfairly neglected because of the similarity with the kind of hemp that is illegal and is used as a narcotic. The objective of this study was to evaluate the oil extraction process from Cannabis sativa seeds by cold pressing followed by extraction with supercritical CO2. In pressing experiments, the response surface methodology was conducted in order to study the effects of temperature, frequency and Nozzle Size on oil recovery and quality parameters. The optimal condition to obtain the highest oil recovery and the best oil quality within the experimental range of the variables studied was at temperature of 60 °C, frequency of 20 Hz and using Nozzle of ID 6 mm. The residual oil in the press cake was totally extracted by supercritical CO2 in newly designed and built supercritical fluid extraction system. The oregano essential oil was the most effective in protecting the oil from oxidative deterioration.
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pressing and supercritical co2 extraction of camelina sativa oil
Industrial Crops and Products, 2014Co-Authors: Tihomir Moslavac, Krunoslav Aladic, Stela Jokic, Drago Subaric, Josipa Vukoja, Nikolina PrceAbstract:Abstract The objective of this study was to evaluate the oil extraction process from Camelina sativa (L.) Crantz seeds by screw pressing followed by extraction with supercritical CO2. In pressing experiments, the response surface methodology (RSM) was conducted in order to study the effects of temperature, frequency and Nozzle Size on oil recovery and quality parameters. The optimal condition to obtain the highest oil recovery and the best oil quality within the experimental range of the variables studied was at temperature of 52 °C, frequency of 20 Hz and using Nozzle of ID 9 mm. The experimental values agreed with those predicted, thus indicating suitability of the used models and the success of RSM in optimizing the pressing conditions of investigated system. The cake resulting from pressing at optimal conditions was extracted with CO2 in a new designed and built a homemade supercritical fluid extraction system. The residual oil in the pressed cake was almost totally extracted by supercritical CO2. The aim of this study was also to investigate the influence of natural antioxidant (rosemary extract Oxy.Less CS, Oxy.Less CLEAR and StabilEnhance OSR, green tea extract, olive leaf extract, pomegranate extract) on the oxidative stability of C. sativa oil. The rosemary extract Oxy.Less CS in concentration of 0.3% was the most effective in protecting the oil from oxidative deterioration.
